1. Field of the Invention
This invention relates to a communication terminal which uses an image data processed based on an image processing request that is sent to an image processing server connected via a communication line.
2. Description of the Related Art
Hitherto, research and development on an image diagnosis apparatus such as CT (computed tomography) and MRI (magnetic resonance imaging), and a three-dimensional medical image technology using an image provided by the image diagnosis apparatus have been conducted. Particularly, an image diagnosis based on volume data processing is widely conducted. An enormous calculation amount is required to perform volume data processing, and therefore in some cases a powerful image processing server on a network has been made to perform calculation.
FIG. 16 shows an image processing system wherein a client terminal 11 and an image processing server 15 are connected via a network 18, and volume data is processed in the image processing server 15. When a job (image processing request) is transmitted from the client terminal 11 via the network 18 to the image processing server 15, the image processing server 15 calls up the volume data corresponding to the job of the client terminal 11 from a database 85 storing volume data, and performs predetermined image processing. The processing result image is transferred via the network 18 to the client terminal 11, and is displayed on a display of the client terminal 11.
FIG. 17 shows a flow of data from the client terminal 11 to the image processing server 15 in the image processing system in the related art at normal time. Since the client terminal 11 does not have sufficient resources for image processing, an image processing request for an image to be displayed on the client terminal 11 is transmitted via the network 18 to the image processing server 15.
FIG. 18 shows a flow of data from the image processing server 15 to the client terminal 11 in the image processing system in the related art at normal time. The image processing server 15 stores volume data 16 which is an image data of the inside of a human body photographed in a CT apparatus, etc., and an image processing program 17 for performing image processing of volume rendering, etc., on the volume data 16.
The image processing server 15 performs image processing responsive to the image processing request from the client terminal 11, and transmits the processing result image to the client terminal 11. Then the client terminal 11 displays the received processing result image on a display 14.
FIG. 19 is a flowchart for executing a job in the image processing system in the related art.
For example, if the user wants to see the CT image of a predetermined part of a human body, user entry is performed in which the user specifies the predetermined part (step S51) at the client terminal 11, and a job is generated (step S52). The client terminal 11 starts processing of the job (step S53), and transmits the job via the network 18 to the image processing server 15 (step S54).
The image processing server 15 calls up the data corresponding to the job from the volume data 16, generates an image (step S55), and transmits the generated image via the network 18 to the client terminal 11 (step S56). The client terminal 11 receives the image (step S57), displays the image on the display 14, and the job is completed (step S58). (For example, refer to “Distributed Visualization. How to improve the quality of medical volume rendering at almost no costs.”, Markle, Steffen; Spikermann, Axel: Proceedings of EuroPACS '98, pp. 225-228, Barcelona, Spain, October 1998.)
However, in the image processing system in the related art, when communication between the client terminal 11 and the image processing server 15 is not normally performed, no action can be taken by the client terminal 11 and work may be interrupted.
FIG. 20 shows a state when communication is disconnected in the image processing system in the related art. FIG. 20 shows a state in which the network 18 is disconnected; one such example is the case where the client terminal 11 is a wireless terminal and moves to the outside of the communication range with the image processing server 15. In such a case, the client terminal 11 cannot access the volume data 16 in the image processing server 15, and image processing and image display work are interrupted.